User name E.Chudakov
Log entry time 21:56:49 on July27,2006
Entry number 175594
14:15-21:30 we tried to do Moller measurements.
It was not successful. The background, presumably from
the radiative Mott was high. Accidental coincidences between
2 arms at about 0.1uA were about 4000 Hz, at the same level
as the expected rate of Moller coincidences. However, the acceptance
for the Moller events is tiny and very sensitive to the fields in
the first 2 quads, and also sensitive on our knowledge of the
geometry. A 10% smaller aperture in certain palces would kill
all the Mollers. We scanned the field in 2 quads but have not
produced a significant Moller signal.
For detector calibration we set up a special setting to detect the
regular Mott scattering. This produced good signals in the
detectors. From that we could extrapolate to the 1/2 of the observed
energy in order to see where to expect the Moller signals.